Combination linkage type rubber crawler

ABSTRACT

In a connected link type rubber crawler for use in a mobile construction machine, track links are connected on the inner periphery of the main body of a crawler made of rubber to form a continuous wheel turning track, and the main body of the crawler and the track links are easily and rigidly connected to each other. In order to connect the track link to the main body of the crawler, a pin is inserted through a hollow hole in an embedded member embedded and fixed in the main body of the crawler, and through a pin hole in the track link and locked against dislodging. The pin is directly embedded and fixed in the main body of the crawler, or the track link is fixed to an embedded member through bolting.

FIELD OF THE ART

The present invention relates to a rubber crawler to be mounted in atransportable type construction machine, etc., especially a preferablecombination linkage type rubber crawler which is mounted in a vehicle ofsuch a type as both steel crawler and rubber crawler are concurrentlyused.

BACKGROUND OF THE INVENTION

Mainly, steel crawlers have conventionally been utilized as crawlermounted in transportable type construction machines, etc. Rubber shoeshave been used in some of the steel crawlers. Recently, rubber crawlersare preferably utilized.

FIG. 1 is a sectional view showing an example of conventional steelcrawlers; 11 is an outer flanged rolling wheel, 12 is a steel crawlershoe, 12a is a shoe plate, 12b is a shoe link, 12c is a linkage pin, and12d is a lug (steel made).

FIG. 2 is a sectional view showing an example of rubber shoe; 13 is arubber shoe, 13a is a shoe plate, 13b is a shoe link, 13c is a linkagepin, and 13d is a rubber lug.

FIG. 3 is a sectional view showing a conventional rubber crawler; 14 isa rubber crawler, 14c is a lug, 15 is a core member, and 16 is a steelcord.

In FIGS. 1 through 3, the same outer flanged rolling wheel can beconcurrently used as rolling wheel in any case.

Hence, steel crawlers have the following advantages;

(1) its vibration is small because a continuous rolling track isobtained by combination of the track link at the inner circumference,

(2) Crawler come-off is scarce because there is no elongation nor phaseerror in the circumferential and width directions, and

(3) the durability is good because mechanical combination of respectivelinks, etc. is large,

On the contrary, the steel crawlers inherently have the followingdisadvantages;

(1) Noise level is high,

(2) Cushioning is not good, and an operator is subjected to a great dealof fatigue, and

(3) Road surface is much damaged.

However, rubber crawlers have such advantages as mentioned below;

(1) Noise level is low,

(2) Cushioning property is good, and fatigue of an operator is low,

(3) Road surface is not damaged, and

(4) The weight is comparatively light, and the running speed can be madecomparatively high according thereto and in line with the aboveproperties.

But, the rubber crawlers have the following shortcomings;

(1) Core members which project on the inner circumference at every fixedinterval are provided and utilized as rolling track. Accordingly,rolling wheels are likely to drop between the fore and back projections,thereby causing the vibration to be made somewhat large,

(2) Owing to that steel cords as elongation resisting member are buriedslightly wave-like, and a thin rubber layer intervenes in theintermediate portion in the piled up area at both the ends of thesesteel cords, the crawler may be elongated when a remarkably highelongating force is given in the circumferential direction or thecrawler itself may be distorted between the core members when anexternal force is given in the lateral width direction or come off dueto those causes, and

(3) The mechanical strength of rubber crawlers is based upon rubbersubstance, and adhering force between core members and steel cords, andit is influenced upon the adhering force at the boundary between metaland rubber. The mechanical strength is much inferior to that of thesteel crawler. Accordingly, the durability of rubber crawler is inferiorto that of steel crawler.

From such circumstances, rubber shoe composed so that rubber lug isprovided at the grounding side of shoe plate of the steel crawler hasbeen partially utilized. The rubber shoe. As for the rubber shoe, it ismade so that a shoe plate and non-vulcanized rubber are arranged inposition in a metal mold and are press-vulcanized, and a rubber lug isadhered to the surface of the shoe plate at the same time as that of thevulcanizing molding.

However, in such a rubber shoe,

(1) The adhering point between shoe plate and rubber lug will be theweakest point in the composition of steel crawlers,

(2) As the rubber shoe will be composed that it is compressed betweenthe shoe plate as steel structure and the ground and will have no spaceof escape, damage of the rubber lug will be promoted,

(3) As the shoe plate is considerably spaced toward the outercircumference to a linkage pin at a part where the shoe plate is woundand turned over, the interval between the fore and back shoe plates willbe opened. For that reason, it is impossible to continue the rubber lugacross the interval of shoe plates, and soil and mud may enter betweenshoe plates on weak road surface to cause a shortage of floating. Inorder to improve this, if the width of shoe plate is increased to reducethe ground-contacting pressure, the total weight may be also increased,instead, its bouyancy is lowered and it will be a change for the worse.

(4) Method for press-vulcanizing individual shoe plates by metal moldwill bring remarkable cost-up.

As a result, such an improved rubber crawler will not be what issuperior to mere rubber crawlers.

DISCLOSURE OF THE INVENTION

The present invention aims at solving the above shortcomings, that is,defects of rubber crawlers are going to be solved with advantages ofsteel crawlers.

COMPOSITION OF THE FIRST INVENTION

Firstly, the first invention is characterized in that as mentioned inclaim 1, a pin is fitted and inserted in a pin hole which lies fore andback of respective track links opposed to each other, in a rubbercrawler having a pair of track link which is continuous in thecircumferential direction at the inner circumferential side of thecrawler body, and both the side ends of the pins are buried in thecrawler body.

According to the invention, the defects of conventional rubber crawlerscan be solved and improved as follows, under such conditions that suchadvantages provided in conventional rubber crawlers as, namely, lownoise level, good cushioning, and little fatigue of an operator can bemaintained.

(1) As a track link will be combined and will become a continuousrolling track at the inner circumferential side of the crawler body,vibration will be made smaller during use of a vehicle in which thecorresponding crawler is adopted.

(2) Such a composition that a pin is fitted and inserted in a pin holewhich lies fore and back of respective track links opposed to eachother, and both the side ends of the pins are buried in the crawler bodywill make it strong the combination of the crawler body with the tracklink, and at this time, since the track links are mechanically combinedstrongly, the following advantages can be further obtained.

1 The crawler come-off will hardly occur during use since almost noelongation of the crawler in the circumferential direction anddistortion in the width direction will occur.

2 The strength of combination of track links will directly constitutestrength of rubber crawler as it is. Accordingly, the durability can beincreased.

3 Since sufficient anti-tension force is held in the circumferentialdirection, and moreover elongation will not occur, use of steel cordsindispensable for the conventional rubber crawlers can be excluded.

(3) As the track link will be made a rolling track, use of core membersindispensable for the conventional rubber crawler can be excluded.

(4) As steel cords and core members are not needed, cost-down can beaccomplished to a large extent as total.

(5) Since a projection of core member is no more needed, a metal moldwill be made thinner in thickness than the conventional ones. Therefore,further cost-down can be attempted at such a standpoint as the heattransmission can be increased.

(6) As track links which have been used in part of conventional steelcrawlers can be used as they are, it is very advantageous.

(7) As the central portion of core member can be formed to any sectionalshape regardless of the tooth bottom of a drive wheel, production costof the core member is comparatively cheap.

In the present invention, it is better that respective track links aremade thin at the fore and back parts thereof, namely, in the mutuallyopposed relationship in the thickness direction at the circumferentialportion of pin hole and mutual combination thereof is carried out underthe same thickness condition.

Besides, there is no problem that both the side ends of pin which isfitted and inserted in the pin hole of the track link are directlyburied in rubber substance of the rubber crawler body (claim 2).However, in order to strengthen the burying strength thereof, generally,burying member may be used together. In details, for example, asmentioned in claim 3, a burying member consisting of two tubular partsburied in the rubber crawler body and an intermediate part forsupporting these tubular parts linearly with a fixed interval spaced isfaced sideways, and is arranged at every fixed interval in thecircumferential direction, and the pins fitted and inserted in the pinhole of track link are inserted and fixed in a hole of the two tubularparts like erection. At that time, a hole of respective tubular parts isopened to the side of the crawler body with the total length of theburying member agreed with the lateral width of the crawler body, and anut is screwed in and provided at both the side ends of the pin insertedin the two tubular parts as come-off prevention means (claim 6). Orinstead of the above, one of the tubular parts is made shorter, the holeof the shorter tubular part is clogged with rubber substance of thecrawler body and it is not opened to one side. On the other hand, a holeof the longer tubular part is opened to the other side of the crawlerbody, and a nut which is provided as come-off prevention means may bescrewed in and provided at one end of the pin fitted and inserted in thetwo tubular parts (claim 7). In the case that lug is provided at thecircumferential side of the crawler body corresponding to each of thetubular parts (claim 8), load acting on the crawler body can besupported under such a condition that its deflection may not be likelyto be generated, and vibration during running can be lightened.

The track links must be kept as pair at a fixed distance from the othertrack links opposed thereto. For that reason, for example, a bushinghaving a fixed length is fitted at the position between respective tracklinks of the pin fitted and inserted in the pin hole of a pair of thetrack links (claim 4). In addition, the above composition may beprovided by any other prompt means not using the bushing.

The bushing or the pin in the case that the bushing is not utilized willbe engaged to the teeth of a sprocket which drives or guides the crawlerbody. At that time, the sectional circumferential shape of the bushingor the sectional shape of the pin are made coincident with the toothprofile of the above sprocket (claim 5).

It is preferable that as mentioned in claim 10, a circumferentiallycontinued thickness-reduced part is provided at the upper edge at theside of circumferential recess groove formed at the intermediate part ofthe above burying member. If so constructed, even though the rollingtrack formed by the track link is inclined sideways due to rockingdisplacement of the whole crawler, the rolling wheel will not come intocontact with the crawler body, and the crawler body can be preventedfrom damages.

As mentioned in claim 9, the crawler body which will be the outercircumference of the tubular parts of the burying member can have areinforcement core buried. If so, it is possible to increased thestrength against load partially acting on the position betweenrespective burying members.

Moreover, the crawler body may be made of urethane rubber, urethaneresin, hard rubber or plastic elastic body, etc., in addition to rubberelastic body (claim 12).

COMPOSITION OF THE SECOND INVENTION

The second invention is characterized by a rubber crawler in which aburying member as a core member is buried at a fixed interval with thelengthwise direction thereof and at a right angle to the circumferentialdirection of the crawler body. The lug is projected circumferentially.

The burying member consists of flat-shaped right and left wing portionsand a recess-shaped central portion. Mounting means like bolts, welding,etc., for mounting track links is provided at both the sides of thecentral portion.

The right and left wing portions of the burying member are buried in therubber substance of the crawler body, and at the same time the positionof the above mounting means is exposed at least to the innercircumferential side of the crawler body or is coated with a thin rubberlayer.

On the other hand, a pin hole is provided at both the sides of the tracklink, mounting means for mounting a burying member is provided at theunderside between the pin holes, and the interval between the pin holesis equal to the interval of the central portions of the adjacent buryingmembers. Furthermore, the track links are mounted from the innercircumferential side of the crawler so that respective burying membersare aligned with the position of the mounting means in the up and downdirection, and at the same time the upper side edge of the link isprojected by a fixed height above the rubber crawler body. On the otherhand, pins are fitted and inserted in pin holes which make the fore andback track links aligned with each other at the intermediate position ofthe adjacent burying members and are combined so that the track linkspivot with respect to one another.

Thereby a track by means of a pair of continuous track links is formedat both the sides of the central portion of the crawler body.

In the present invention, as well as the first invention, since acontinuous rolling track is formed by combining track links at the innercircumferential side of the rubber crawler, advantages similar to theabove can be obtained in relation to the above. Also, in the presentinvention, as an example of the mounting means the track links arecombined with bolts by installing bolt holes at both the sides of thecentral part of the burying member. As another example of the mountingmeans respective mounting positions of the burying member and tracklinks are welded and combined by aligning them in the up and downdirection. For that reason, the work of mounting the track links can becomparatively easily carried out. Moreover, rubber crawlers can becomparatively easily and cheaply manufactured as a whole.

In the present invention, it is better that the crawler body between theburying members is bent and curved to be high toward the innercircumferential side (claim 13). If so composed, since the height of thecrawler body is made almost equal to that of the link pins, this portionis almost free from any elongation while it is placed on the curvaturepart of the drive wheel or idle wheel, and a lowering of the durabilityof the rubber crawler will not from accumulation of fatigue throughrepeated elongation.

The right and left wing portions of the burying member can be shaped soas to be like a sweptback wing shape relative to the central portion; alug can be provided at the outer circumferential side of the crawlerbody corresponding to the right and left wing portions; and a part ofthe lug can be located on the extension of the centerline of the linkpin (claim 14). Thus, as this portion will hardly drop even when therolling wheel rides on the link pin, vibration during running can bereduced to a large extent.

It is possible to provide a reinforcement layer continuous in thecrawler body and in the circumferential direction passing in thevicinity, in the up and down direction of both the right and left wingportions of the burying member in the up and down direction (claim 15).Thus, even in the case that the crawler body rides on a projection onthe road surface, the crawler body will not be damaged due to remarkableelongation.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional view showing an example of conventional steelcrawler;

FIG. 2 is a sectional view showing an example of conventional rubbercrawler; and

FIG. 3 is a sectional view of the conventional rubber crawler.

FIG. 4 through FIG. 9 relate to the first invention;

FIG. 4 is a perspective view of of burying member;

FIGS. 5A, 5B and 5C show a rubber crawler in which the burying member isbuilt;

FIG. 5A is the plan view thereof;

FIG. 5B is the front elevational view thereof; and

FIG. 5C is the sectional view taken along the line X--X of

FIG. 5A; FIGS. 6A and 6B show a track link;

FIG. 6A is the plan view thereof,

FIG. 6B is the front elevation view thereof;

FIG. 7 is a partially broken perspective view of one of the preferredembodiments,

FIG. 8 is a sectional view of the preferred embodiment, and

FIG. 9.is a view showing another preferred embodiment.

FIG. 10A through FIG. 20B relate to the second invention,

FIG. 10A through FIG. 14B are views for the first preferred embodiment;FIGS. 10A, 10B and 10C show a burying member to be used in the preferredembodiment;

FIG. 10A is a perspective view;

FIG. 10B is a side view;

FIG. 10C is a top plan view;

FIG. 11A, 11B and 11C show the crawler body;

FIG. 11A is the plan view thereof;

FIGS. 11B and 11C are the sectional views taken along the lines X1--X1and X2--X2 of FIG. 11A;

FIG. 12 is a perspective view of the rubber crawler body;

FIGS. 13A and 13B show a, track link to be used in the preferredembodiment;

FIG. 13A is the front elevational view thereof;

FIG. 13B is the bottom view thereof, and

FIGS. 14A and 14C are views partially showing the status under which thetrack link is installed on the rubber crawler body;

FIG. 14A is the front elevation view thereof,

FIG. 14B is the sectional view thereof;

FIG. 15 is a view explaining the turning and winding status of acombination linkage type rubber crawler of the present invention ontothe drive wheel or the idle wheel;

FIG. 16A is the plan view of the burying member to be used in thepreferred embodiment;

FIG. 16B is the plan view at the outer circumferential side of therubber crawler side;

FIG. 17 shows the third preferred embodiment of the present invention;

FIG. 17A is the plan view of the burying member to be used in thepreferred embodiment;

FIG. 17B is the plan view at the outer circumferential side of therubber crawler body;

FIG. 18A through FIG. 20B show the fourth preferred embodiment of thepresent invention;

FIGS. 18A-18D show the burying member to be used in the preferredembodiment;

FIG. 18A is a perspective view thereof;

FIG. 18B is the plan view thereof;

FIG. 18C is the side view in the width direction thereof;

FIG. 18D is the side view in the lengthwise direction thereof;

FIGS. 19A and 19B show a track link to be used in the preferredembodiment;

FIG. 19A is the front elevational view thereof;

FIG. 19B is the bottom view thereof; and

FIGS. 20A and 20B show a rubber crawler body;

FIG. 20A is a view of partial status under which the track link isprovide; and

FIG. 20B is the plan view at the outer circumferential side.

A PREFERRED EMBODIMENT OF THE FIRST INVENTION

Firstly, a preferred embodiment related to the first invention isdescribed with reference to FIG. 4 through FIG. 9.

In FIG. 4, 1 is a pin having screw portions 1a and 1b, 2 is a buryingmember; 2a and 2a are tubular portions; 2b is the intermediate portionthereof; H is a hollow hole inside the tubular portions 2a, and theouter diameter of the pin 1 is designed with such dimensions that it canbe promptly fitted to the hollow hole H.

FIGS. 5A, 5B and 5C show a rubber made crawler body 3 in which the aboveburying member 2 is buried; FIG. 5A is the plan view thereof; FIG. 5B isthe front elevational view thereof; FIG. 5C is a sectional side viewtaken along the line X--X of FIG. 5A, 4 represents a recess groove, 5 isa lug provided corresponding to respective tubular portions 2a at theouter circumferential side of the crawler body 3. In the presentpreferred embodiment, the width W of the recess groove 4 is made equalto the interval of the intermediate portion 2b of the burying member 2,and a hollow hole H is opened through at the counter faces u, u wherethe burying member 2 of the recess groove 4 is located, and the lengthof the burying member 2 is made equal to the lateral width of the rubbercrawler 3 and a hollow hole H is opened through at both the sides S, Sof the rubber crawler 3. Also, P represents the interval of the buryingmember 2.

FIGS. 6A and 6B show a composition of the track link; FIG. 6A is theplan view thereof; FIG. 6B is the front elevational view thereof; H' isa pin hole; g is the upper side edge, t is the thickness, respectively.Herein, the interval l between the right and left pin holes is formed tothe dimension equal to the interval P of the burying member 2, and atthe same time, the vicinity portion of the pin holes H' is made thinnerin the thickness (half the thickness t) in a mutually opposedrelationship at the right and left positions, thereby causingcombination of the fore and back track links 6 to be made with the samethickness. Also, the upper side edge g is formed to be flat and will actas rolling track.

FIG. 7 is a partially broken perspective view of the present preferredembodiment, track links 6, 6, . . . are arranged in a row in thevicinity of both the sides u, u of the recess groove 4, and the pin 1 ispenetrated through the pin holes H' and hollow hole H which are piled upin the fore and back direction. At that time, E is a bushing externallyfitted to the pin between mutually opposed track links 6, 6, and acts asspacing means of the two track links 6, 6. In the present preferredembodiment, this bushing E will be designed to be engaged with the teethof sprocket. Furthermore, another means may be available as spacingmeans between the right and left track links. It is necessary to providean adequate come-off prevention means in order to prevent the pin 1 fromdropping from the hollow hole H of the tubular portions 2a, 2a, but inthe present embodiment, a nut is screwed and fixed to a screw portion1a.

FIG. 8 is a sectional view of the present preferred embodiment, as showntherein, the upper side edge g of the track link 6 will be a rollingtrack on which the rolling wheel T rotatingly moves. However, k is athickness reduced portion which is continuously provided on the upperedge of the side u (Refer to C in FIG. 5) of the recess groove 4, andprevents in advance the rubber substance of that area from being scoopedout due to that the outer flange of the rolling wheel T is brought intocontact with the rubber substance of that area owing to lateral rollingof the equipment body in the case that the thickness-reduced portion kis not provided. In the Figure, N is a nut screwed and fixed to thescrew portion 1a.

FIG. 9 shows another preferred embodiment of the invention. As showntherein, it is such that a reinforcement core F is buried at the outercircumferential side of the tubular portions 2a of the burying member 2.The point thereof is as follows; Namely, in the preferred embodiment,since the track link 6 is firmly combined with the whole circumferenceof the crawler body 5, there is no need to bury elongation resistingmembers like steel cords, etc. which are indispensable to conventionalrubber crawlers. Since the crawler body 5 between the fore and backburying members 2, 2 is made only of rubber substance and has noreinforcement core, it is because of preventing in advance that portionfrom being damaged through extraordinary elongation due to riding onobstacles like stones. Furthermore, the reinforcement core F may be ofnatural or artificial fibers or fabric of metal fibers, or these fibercords may be used. Moreover, a small quantity of steel cords may be usedinstead.

In the above preferred embodiment, as for the burying member 2, one ofthe tubular parts 2a is made shorter, and come-off prevention means maybe installed only at the side S of the crawler body 5 at the side wherelonger tubular part is buried.

Also, it is all right that a pin 1 is directly buried in the crawlerbodies 3, 3 without use of the burying member 2. In this case, a tracklink 6 in which a pin 1 is fitted and inserted is arranged in along-sized metal mold together with non-vulcanized rubber, andpress-vulcanized, thereby causing the pin 1 to be buried at the sametime when the crawler body 5 is vulcanized and molded.

In the present invention, rubber substance of the crawler body 5includes usual rubber elastic body, urethane rubber, or urethane resin,other hard rubber, or plastic elastic body.

A PREFERRED EMBODIMENT OF THE SECOND INVENTION

A preferred embodiment of the second invention is described withreference to FIGS. 10A, 10B and 10C through FIGS. 20A and 20B. Then, thesame symbols are given to the parts substantially identical to those inthe first invention.

FIGS. 10A, 10B and 10C show a burying member or core bar 2 to be used inthe first preferred embodiment of the present invention; FIG. 10A is aperspective view; FIG. 10B is a side view, and FIG. 10C is the topsurface view. In the Figures, 21a, 21a are right and left wing portions,21b is a recess-shaped central portion, H1, H1 are bolt holes (throughholes) provided at both the sides of the central portion 21b, h is astep by which the central portion 21b is located at a lower level thanthe wing portions 21a.

FIGS. 11A, 11B and 11C show a rubber-made crawler bodies 31, 31 in whichthe burying member or core bar 21 is buried; FIG. 11A is the plan viewthereof: FIGS. 11B and 11C are the sectional views taken along the linesX1--X1 and X2--X2 of FIG. 11A. As shown therein, the right and left wingportions 21a, 21a are buried in the rubber substance of the crawler body31, and at the same time, the periphery of of the bolt holes H1, H1 atthe central portion 21b is not buried. However, the central portion 21bcan be shielded with rubber substance having optional thickness,excluding the periphery of the bolt holes H1, H1 at the innercircumferential side.

A curvature part is defined in the crawler body between the wingportions 21a, 21a which are adjacent to each other in thecircumferential direction, the curvature part curving to be high towardthe inner circumferential side; 23 is a reinforcement layer continued inthe circumferential direction; as shown in the drawing, in the presentpreferred embodiment, the reinforcement layer 23 is made wave-like as itis buried through the lower side of the wing portion 21a; 24 is a lugprojected on the outer circumferential face corresponding to the wingportion 21a. FIG. 12 is a perspective view of the above rubber crawlerbody 31.

FIGS. 13A and 13B show a piece of the track link 61 to be used in thepresent preferred embodiment; FIG. 13A is the front elevational viewthereof; FIG. 13B is the bottom view thereof; it is the same as thatwhich has been used in a part of the conventional steel crawlers. In theFigure, H' is a pin hole; the interval l between the right and left pinholes H', H' is made with the dimension equal to the interval of theburying member 21; 27 is a window; 28 is a lower frame of the window 27;p1 is a bolt hole for installing the track link 61 at the central part21b of the burying member 21; As shown in the drawing, the bolt hole p1is penetrated through the lower face f of the track link from the upperface 28a of the lower frame 28. Furthermore, the upper face g of thetrack link 61 is made flat and acts as rolling track. The vicinity partaround the right and left pin holes H', H' is made thinner in thickness(half the thickness t) in mutually opposed relationship in the right andleft positions, thereby causing combination of the fore and back tracklinks 61 to be achieved under the same thickness condition. According tothe above combination, a pair of the track links 61, 61 are verticallyprovided at both the sides of the central part 21b by making the abovebolt hole p1 coincident with the bolt hole H1 of the central part 21b ofthe burying member or core bar 21 and fixing the mutually communicatedbolt holes p1 and H1 with a bolt, simultaneously respective pin holes ofthe fore and back track links 61, 61 are piled up; a link pin isrotatably inserted in the piled up pin holes H', H', thereby causing thetrack links to be combined and continued. Thus, the track links can actas rolling track.

FIGS. 14A and 14B are a view of partial status under which the tracklinks 61 are mounted at the crawler body 31 of the present preferredembodiment; FIG. 14A is the front elevational view thereof; FIG. 14B isthe sectional view thereof; In the Figure, 29 is a link pin.Furthermore, B1 is a bolt, N1 is a nut.

Hereupon, the mounting means of the burying member 21 and the tracklinks 61 may be welding as well as bolt-fastening means, and any othermeans may be acceptable.

The mounting position is not limited to the central position of thetrack links 61, and the burying member and track links may be mounted atany optional position between the right and left pin holes H', H'.

FIG. 15 explains the turning and winding condition on the drive wheeland idle wheel of the combination link type rubber crawler according tothe present invention. At the turning and winding portion, the outercircumferential side from the connecting line of link pins 29, 29, . . .is elongated, and the ratio of elongation will be made larger toward theouter circumferential side. On the other hand, at the crawler body 31,the burying portion of the burying member is not elongated, and theinterval between the burying members is elongated. Accordingly, as theratio of elongation of this portion becomes large, the fatigue isaccumulated due to repeated elongation to spoil its durability. However,in the present preferred embodiment,

(1) As a step h is provided between the wing portion 21a of the buryingmember 21 and the central portion 21b to lower the central portion 21b,the track links 61 are designed to be mounted at a comparatively lowposition,

(2) As a curvature 22a is provided between the burying members 21 of thecrawler body 31, this portion will be made higher toward the innercircumferential side and its height thereof is made almost equal to thatof the link pin 29. For that reason, almost no elongation occurs at theturning and bending portion. Therefore, a problem of fatigueaccumulation will not occur.

Hereupon, in the case that the crawler body 31 between the above buryingmembers 21 is made of only rubber substance, this portion rides on aprojection on the road surface and may be damaged due to beingremarkably elongated. In order to prevent that in advance, areinforcement layer 23 may be buried. Natural or artificial fibershaving high strength, or fabrics of metal fibers, or the fiber cords,thereof may be used as reinforcement layer 23; a small quantity of steelcords may be used, too. It is preferable that the burying position ofthe reinforcement layer 23 is to almost the same height as the link pins29 in the crawler body 31 due to the above reason. If necessary, thereinforcement layer may be provided in a plurality, and stillfurthermore may be buried at the top of the burying members.

FIGS. 16A and 16B show the second preferred embodiment of the presentinvention; FIG. 16A is the plan view of burying member 211 to be used inthe present preferred embodiment; FIG. 16B is the plan view at the outercircumferential side of the rubber crawler body 32 according to thepresent preferred embodiment. As shown in FIG. 16A, in the buryingmembers or core bars 211, the right and left wing portions 211a, 211aare shaped so as to be like sweptback wing to the central portion 211b(Sweptback angle: θ). A lug 241 is provided at the outer circumferencein response to the wing portion 211a with the burying member 211 buriedin the rubber crawler body 32; as shown in FIG. 16B, a part of the lugis designed to be located on the extension line of the centerline O ofthe link pin 29, and the rolling wheel is almost free from any drop atthis portion, thereby causing vibrations during running to be muchlightened.

FIGS. 17A and 17B show the third preferred embodiment of the presentinvention; As shown in FIG. 17A, the right and left wing portions 212a,212a of the burying member or core bar 212 are formed to be stepped,respectively. A lug 242 is provided at the outer circumferencecorresponding to the wing portion 212a with these wing portions buriedin the rubber crawler body 33 as well as in the above preferredembodiment; as shown in FIG. 17B, a part of the lug 242 is located onthe extension line of the centerline O of the link pins 29, therebycausing the same effects as those in the second preferred embodiment tobe obtained.

FIGS. 18A-18D show a burying member 213 to be used in the fourthpreferred embodiment of the present invention; FIG. 18A is a perspectiveview thereof, FIG. 18B is the plan view thereof, FIG. 18C is a sideelevational view in the lengthwise direction, and FIG. 18D is a sideelevational view in the width direction. In these Figures, m, mrepresent projections provided at the side close to the central part ofthe right and left wing portions 213a, 213a; n, n represent centralprojections provided at both the sides of the central portion 213b; boltholes H, H are pierced and provided at both the central projections n.For that reason, as shown therein, bolt holes H, H are providedparallelly with the interval l1 at both the sides of the central portion213, respectively.

FIGS. 19A and 19B show a piece of the track links 62 to be used in thepresent invention; FIG. 19A is the front elevational view thereof; FIG.19B is the bottom view thereof. As shown in these Figures, bolt holesp2, p2 are provided at two points of the lower frame 28, and theinterval l2 is secured with the dimension equal to the interval l1between bolt holes at the central portion 213b of the above buryingmember 213.

FIGS. 20A and 20B show a rubber crawler of the above preferredembodiment; FIG. 20A is a view of partial status under which the tracklinks 62 are mounted at the crawler body 34; As shown therein, the tracklinks 62 are fixed with bolts together with the central portions 213b ofthe burying member at two points. FIG. 20B is the plan view at the outercircumference of the crawler body 62. As shown therein, a lug projection243a is provided at the side of the lug 243 corresponding to the centralprojection portion m of the burying member 213, and the lug projection243 is designed to be located on the extension line of the centerline Oof link pin 29 of the track link 62. For that reason, the rolling wheelis free from any drop at the position of the link pins 29, therebycausing vibrations during running to be much reduced. Furthermore, 34ais a portion curved to the inner circumferential side of the crawlerbody 34.

In the above combination linkage type rubber crawler of the presentinvention, the link pins 29 are engaged with the drive wheel to transmitdrive force, and the central portion of the burying members or core bars21, 211, 212, and 213 may be of any optional sectional shape regardlessof the tooth bottom of the drive wheel. For that reason, the productioncost of burying members or cores bars will be comparatively cheap.Besides, track links 62, 62 which have been manufactured for the sake ofconventional steel crawlers can be utilized as they are. Thus, it isvery advantageous.

FIELD OF INDUSTRIAL APPLICATION OF THE INVENTION

As described above, a combination linkage type rubber crawler isutilized for a running device of transportable type constructionmachines, etc. Especially, it is most preferable for such a vehicle asin which steel crawler and rubber crawler can be concurrently used.

What is claimed is;
 1. In a rubber crawler having a crawler body andburying members buried in the crawler body at a fixed interval, eachburying member having a lengthwise direction at a right angle to thecircumferential direction of the crawler body, and the crawler bodyhaving a lug provided on and projecting from the outer circumference ofthe crawler body, the improvement comprising:each burying membercomprises right and left flat-shaped wing portions and a central portionhaving mounting means to fix track links spaced apart on the centralportion; the crawler body comprises a rubber substance, the right andleft wing portions are buried in the rubber substance of the crawlerbody, and the central portion is either exposed at least to an innercircumferential side of the crawler body or shielded with a thin rubberlayer; the track links have opposite ends and a pin hole adjacent toeach of said ends, mounting means for mounting each of said track linkson a burying member is provided at an underside of each said linkbetween respective pin holes, the interval between the pin holes of alink is equal to the interval between the centers of the centralportions of adjacent burying members, the track links are mounted on theinner circumferential side of the crawler body in alignment with therespective mounting means coupled with each other in the up and downdirection, and the link has an upper side edge positioned at a fixedheight above the rubber crawler body; adjacent pin holes of adjacentlinks are aligned with each other between adjacent burying members, anda pin is positioned in the aligned adjacent pin holes so that theadjacent links pivot relative to one another; whereby a track is formedat the central part of the crawler body by a pair of continuous tracklinks.
 2. A combination linkage type rubber crawler claimed in claim 1,wherein the crawler body between the burying members is bent and curvedso as to become high toward the inner circumference of the crawler body.3. A combination linkage type rubber crawler claimed in claim 2, whereinthe right and left wing portions of the burying member are formed likeswept-back wings or are stepped relative to the central part, and a lugis provided at the outer circumferential side of the crawler body at theright and left wing portions.
 4. A combination linkage type rubbercrawler claimed in claim 2, wherein a circumferentially continuousreinforcement layer is buried inside the crawler body.
 5. A combinationlinkage type rubber crawler claimed in claim 1, wherein the right andleft wing portions of the burying member are formed like swept backwings or are stepped relative to the central part, and a lug is providedat the outer circumferential side of the crawler body at the right andleft wing portions.
 6. A combination linkage type rubber crawler claimedin claim 5, wherein a circumferentially continuous reinforcement layeris buried inside the crawler body.
 7. A combination linkage type rubbercrawler claimed in claim 1, wherein a circumferentially continuousreinforcement layer is buried inside the crawler body.
 8. A combinationlinkage type rubber crawler claimed in claim 5, wherein acircumferentially continuous reinforcement layer is buried inside thecrawler body.
 9. A combination linkage type rubber crawler claimed inclaim 1, wherein the crawler body is made of any one of rubber elasticbody, urethane rubber, urethane resin, hard rubber or plastic elasticbody.
 10. A combination linkage type rubber crawler claimed in claim 1,wherein said central portion of the burying member is recessed relativeto the right and left flat-shaped wing portions.
 11. A combinationlinkage type rubber crawler claimed in claim 10, wherein the crawlerbody is made of any one of rubber elastic body, urethane rubber,urethane resin, hard rubber or plastic elastic body.
 12. A combinationlinkage type rubber crawler claimed in claim 11, wherein the crawlerbody between the burying members is bent and curved so as to become hightoward the inner circumference of the crawler body.
 13. A combinationlinkage type rubber crawler claimed in claim 11, wherein the right andleft wing portions of the burying member are formed like swept-backwings or are stepped relative to the central part, and a lug is providedat the outer circumferential side of the crawler body at the right andleft wing portions.
 14. A combination linkage type rubber crawlerclaimed in claim 11, wherein circumferentially continuous reinforcementlayer is buried inside the crawler body.
 15. A combination linkage typerubber crawler claimed in claim 10, wherein the crawler body between theburying members is bent and curved so as to become high toward the innercircumference of the crawler body.
 16. A combination linkage type rubbercrawler claimed in claim 10, wherein the right and left wing portions ofthe burying member are formed like swept-back wings or are steppedrelative to the central part, and a lug is provided at the outercircumferential side of the crawler body are the right and left wingportions.